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<title>Struct template make_expr&lt;Tag, Domain, A...&gt;</title>
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<h2><span class="refentrytitle">Struct template make_expr&lt;Tag, Domain, A...&gt;</span></h2>
<p>boost::proto::result_of::make_expr&lt;Tag, Domain, A...&gt; — Metafunction that computes the return type of the
            <code class="computeroutput"><a class="link" href="../make_expr.html" title="Function make_expr">proto::make_expr()</a></code>
            function, within the specified domain.</p>
</div>
<h2 class="refsynopsisdiv-title">Synopsis</h2>
<div class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="../../../proto/reference.html#header.boost.proto.make_expr_hpp" title="Header &lt;boost/proto/make_expr.hpp&gt;">boost/proto/make_expr.hpp</a>&gt;

</span><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> Tag<span class="special">,</span> <span class="keyword">typename</span> <a class="link" href="../../../Domain.html" title="Concept Domain">Domain</a><span class="special">,</span> <span class="keyword">typename</span><span class="special">...</span> A<span class="special">&gt;</span> 
<span class="keyword">struct</span> <a class="link" href="make_e_1_3_32_5_31_2_1_2_2.html" title="Struct template make_expr&lt;Tag, Domain, A...&gt;">make_expr</a><span class="special">&lt;</span><span class="identifier">Tag</span><span class="special">,</span> <span class="identifier">Domain</span><span class="special">,</span> <span class="identifier">A</span><span class="special">...</span><span class="special">&gt;</span> <span class="special">{</span>
  <span class="comment">// <a class="link" href="make_e_1_3_32_5_31_2_1_2_2.html#boost.proto.result_of.make_e_1_3_32_5_31_2_1_2_2types">types</a></span>
  <span class="keyword">typedef</span> <span class="emphasis"><em><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span></em></span> <a class="link" href="make_e_1_3_32_5_31_2_1_2_2.html#boost.proto.result_of.make_e_1_3_32_5_31_2_1_2_2.type"><span class="identifier">type</span></a><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="id-1.3.32.5.33.7.4"></a><h2>Description</h2>
<p>
              Computes the return type of the
              <code class="computeroutput"><a class="link" href="../make_expr.html" title="Function make_expr">proto::make_expr()</a></code>
              function.
            </p>
<div class="refsect2">
<a name="id-1.3.32.5.33.7.4.3"></a><h3>
<a name="boost.proto.result_of.make_e_1_3_32_5_31_2_1_2_2types"></a><code class="computeroutput">make_expr</code> 
        public
       types</h3>
<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
<p>
<span class="keyword">typedef</span> <span class="emphasis"><em><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span></em></span> <a name="boost.proto.result_of.make_e_1_3_32_5_31_2_1_2_2.type"></a><span class="identifier">type</span><span class="special">;</span></p>
<p>
                Let <code class="computeroutput"><em class="replaceable"><code>WRAP&lt;X&gt;</code></em></code> be defined such that:
                </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem"><p>
                      If <code class="computeroutput">X</code> is <code class="computeroutput">Y &amp;</code>
                      or (possibly cv-qualified) <code class="computeroutput">boost::reference_wrapper&lt;Y&gt;</code>,
                      then <code class="computeroutput"><em class="replaceable"><code>WRAP&lt;X&gt;</code></em></code> is equivalent to
                      <code class="computeroutput"><a class="link" href="as_child.html" title="Struct template as_child">proto::result_of::as_child</a>&lt;Y, Domain&gt;</code>.
                    </p></li>
<li class="listitem"><p>
                      Otherwise, <code class="computeroutput"><em class="replaceable"><code>WRAP&lt;X&gt;</code></em></code> is equivalent to
                      <code class="computeroutput"><a class="link" href="as_expr.html" title="Struct template as_expr">proto::result_of::as_expr</a>&lt;X, Domain&gt;</code>.
                    </p></li>
</ul></div>
<p>
              </p>
<p>
                If <code class="computeroutput"><a class="link" href="../wants_basic_expr.html" title="Struct template wants_basic_expr">proto::wants_basic_expr</a>&lt;typename Domain::proto_generator&gt;::value</code>
                is true, then let <code class="computeroutput"><em class="replaceable"><code>E</code></em></code> be
                <code class="computeroutput"><a class="link" href="../basic_expr.html" title="Struct template basic_expr">proto::basic_expr</a></code>; otherwise,
                let <code class="computeroutput"><em class="replaceable"><code>E</code></em></code> be
                <code class="computeroutput"><a class="link" href="../expr.html" title="Struct template expr">proto::expr</a></code>.
              </p>
<p>
                If <code class="computeroutput">Tag</code> is
                <code class="computeroutput"><a class="link" href="../tag/terminal.html" title="Struct terminal">proto::tag::terminal</a></code>, then
                <code class="computeroutput">type</code> is a typedef for
                <code class="computeroutput">typename <em class="replaceable"><code>WRAP&lt;A<sub>0</sub>&gt;</code></em>::type</code>.
              </p>
<p>
                Otherwise, <code class="computeroutput">type</code> is a typedef for
                <code class="computeroutput">boost::result_of&lt;Domain(<em class="replaceable"><code>E</code></em>&lt;
                Tag, <a class="link" href="../listN.html" title="Struct template listN">proto::listN</a>&lt;
                typename <em class="replaceable"><code>WRAP&lt;A&gt;</code></em>::type...&gt; &gt;)&gt;::type</code>
              </p>
</li></ol></div>
</div>
</div>
</div>
<div class="copyright-footer">Copyright © 2008 Eric Niebler<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
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